In addition to the above, the US should be aware that it will not be insulated from the far worse catastrophes in some other parts of the world. Bangladesh alone is destined to go largely underwater, displacing up to 100 million people alone from that single country. Similar catastrophes are going to befall other countries without the same resilience Western countries possess in Africa and Asia. The massive famines, refugee movements, wars over resources and related effects will have a worldwide impact. Just the relatively minor refugee exodus from the Middle East and Africa over the last 15 years or so has created tensions with global impact. People have no idea what coming decades have in store.
Not only is far worse climate change inevitable even with serious action, but few countries are committed to quick and meaningful amelioration efforts. The US under Trump is showing a reckless disregard for the planet we all inhabit, but most other countries remain more or less complacent in the face of the clear and present emergency.